Property assessment of heat treated ferrous and non ferrous materials using ultrasonic and eddy current testing methods

Abstract

newline Non-Destructive Testing (NDT) aims to determine, the flaws and discontinuities on the material and to characterize it without destructing it. Eddy Current Testing (ECT) method is based on the magnetic induction principle. It is a reliable, and a cost-effective method among the conventional methods in quality control. There are mainly three types of probes like internal, encircling and surface probes that are used in ECT. The surface probes are used to locate the cracks on the material. Further, these probes are used to sort materials in heat treatment shop floors and case depth measurement. Coil probe is used in the ECT at 690 KHz and the results are obtained in the form of impedance diagram. Ultrasonic Testing (UT) is utilized to identify the internal defects in the material by the reflection of ultrasonic waves from the bottom surface of metals. Acoustic velocity in different specimens is measured using UT machine at a frequency of 4 MHz. Metal Matrix Composites (MMCs) are used mainly in aircraft, electronic packing and automotive because of their better thermal and electrical conductivity, high strength and specific stiffness properties. They are well known for their higher strength to weight ratio. Aluminum based composites have higher thermal conductivity, specific strength and good wear resistance.